Transplantation is a rapidly-expanding, challenging area of clinical medicine with great potential for the cure of many human diseases. This field provides exciting opportunities for the productive interaction between basic scientists and clinicians. The University of Pittsburgh's Starzl Transplantation Institute and Departments in the School of Medicine provide a unique academic environment conducive to the comprehensive, broad-based training of young basic scientists and physicians in transplantation biology with an emphasis on immunology and cell and molecular pathology. We propose an interdisciplinary research program to train graduate and postdoctoral researchers to help ensure that highly-trained investigators are available to assume leadership roles in academia, industry and government-affiliated research. Participating faculty with diverse but complementary research interests, a successful record of productive collaboration and a commitment to training young investigators, will impart skills in transplantation biology, including expertise in immunogenetics, aspects of ischemia-reperfusion injury, antigen-presenting cell and T cell biology, tolerance induction, liver immunology, biology of transplant infectious disease, chronic rejection, composite tissue transplantation, evolution of allo- and xenorecognition, xenotransplantation and novel therapeutic immunosuppressive agents/regimens. The principal goal of this training program is to produce outstanding, potentially independent investigators, able to address fundamental questions in transplantation biology and equipped with appropriate survival and career development skills. Predoctoral trainees will be selected from graduate students enrolled in the Interdisciplinary Biomedical Graduate Training Program at the University of Pittsburgh School of Medicine, who express interest in pursing PhD research in transplantation biology. Support is requested for 2 predoctoral trainees in the initial year and for 4 trainees in subsequent years, distributed between students in their 1st, 2nd, 3rd or 4th year of research. Postdoctoral trainees with MD, PhD, or MD/PhD degrees will be selected based on their outstanding potential and will be supported for 2 years. Support is requested for 2 postdoctoral trainees in the initial year, and for 4 trainees in subsequent years.